1. Field of the Invention
The invention relates to a heating element formed by an electrical resistance, to a liquid container provided with such a heating element, and to a method for detecting a temperature change in a heating element formed by an electrical resistance.
2. Description of the Prior Art
The heating of heating elements, as applied for instance for heating liquid in liquid containers or heating of hot plates, takes place according to the prior art with for instance electrical resistances which are heated by current feed. Examples hereof are for instance a heating spiral which is placed in the liquid container and an electrically heated grill plate. In order to prevent overheating of the heating element such as can for instance in the case of boiling-dry or accumulated scale, the prior art electrical heating elements are usually provided with a separate temperature sensor such that the current feed of a heating element can be limited when the temperature rises too high. The drawbacks of the existing heating elements are that they are usually situated in the liquid for heating, that there is a relatively great risk of undetected overheating and/or that separate provisions have to be made for temperature monitoring.
The object of the invention is to provide an improved heating element and method with which the above stated drawbacks can be prevented while retaining the advantages of the prior art.